Two-part backing rings used to back a roller bearing assembly on a railcar axle are known in the art. In such two-part backing rings, a main body abuts and thus backs (i.e., prevents inboard movement of) a roller bearing assembly used on the railcar axle, and a second piece or locking ring engages both the main body and a railcar axle in an effort to maintain the main body securely in place.
For example, U.S. Pat. No. 7,219,938 describes a two-part backing ring including an annular body (first part) which abuts a fillet of a journal of a railcar axle and which includes a lip extending over the outer cylindrical diameter of a dust guard of the railcar axle, and a stabilizing element (second part) lodged tightly between the lip and dust guard to lessen motion between the lip and the cylindrical surface. However, such a design provides drawbacks because, among other deficiencies, the lip is susceptible to failure (e.g., shearing off) during use as the railcar axle moves with respect to the main body of the backing ring.
Other known two-part backing rings eliminate this lip. For example, U.S. Pat. No. 8,226,299 describes a two-part backing ring including an annular body (first part) which abuts the fillet of the journal of the railcar axle but which does not include a lip extending over the outer cylindrical diameter of the dust guard of the railcar axle. Rather, the annular body includes a slot on an inboard face of the annular body which receives a locking ring (second part), and this locking ring extends out from the slot and over the dust guard. However, this design also includes drawbacks because, among other deficiencies, the locking ring includes an outer and an inner groove, providing a weak middle portion of the ring.